EP0401280B1 - Method for trimming a bandgap voltage reference circuit with curvature correction - Google Patents

Method for trimming a bandgap voltage reference circuit with curvature correction Download PDF

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Publication number
EP0401280B1
EP0401280B1 EP89903320A EP89903320A EP0401280B1 EP 0401280 B1 EP0401280 B1 EP 0401280B1 EP 89903320 A EP89903320 A EP 89903320A EP 89903320 A EP89903320 A EP 89903320A EP 0401280 B1 EP0401280 B1 EP 0401280B1
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EP
European Patent Office
Prior art keywords
resistor
transistors
resistors
voltage
trimming
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EP89903320A
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German (de)
English (en)
French (fr)
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EP0401280A1 (en
Inventor
Stephen R. Lewis
A. Paul Brokaw
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Analog Devices Inc
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Analog Devices Inc
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    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
    • G05F3/00—Non-retroactive systems for regulating electric variables by using an uncontrolled element, or an uncontrolled combination of elements, such element or such combination having self-regulating properties
    • G05F3/02—Regulating voltage or current
    • G05F3/08—Regulating voltage or current wherein the variable is dc
    • G05F3/10—Regulating voltage or current wherein the variable is dc using uncontrolled devices with non-linear characteristics
    • G05F3/16—Regulating voltage or current wherein the variable is dc using uncontrolled devices with non-linear characteristics being semiconductor devices
    • G05F3/20—Regulating voltage or current wherein the variable is dc using uncontrolled devices with non-linear characteristics being semiconductor devices using diode- transistor combinations
    • G05F3/30—Regulators using the difference between the base-emitter voltages of two bipolar transistors operating at different current densities
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S323/00—Electricity: power supply or regulation systems
    • Y10S323/907—Temperature compensation of semiconductor

Definitions

  • This invention relates to circuits for generating stable reference voltages and, in particular, to circuits known as "bandgap" voltage references.
  • the invention is directed to the temperature compensation of bandgap references.
  • a bandgap voltage reference circuit generally employs two transistors operated at different current densities, and means for developing a voltage proportional to the difference in the base-emitter voltages of those transistors (termed ⁇ V BE ).
  • ⁇ V BE base-emitter voltages of those transistors
  • the bases of the two transistors are tied together and a resistor connects their emitters, to sense the difference in V BE ′s.
  • a bandgap reference might more properly be called a V BE reference, as it basically involves the generation of a voltage with a positive temperature coefficient the same as the negative coefficient of a transistor base-emitter junction voltage (i.e., V BE ). When the voltage with the positive temperature coefficient is added to a V BE , the resultant voltage has a zero temperature coefficient in the ideal case.
  • Substantially all bandgap references feature the summation of a base-emitter junction voltage with a voltage generated from a pair of transistors operated with some ratio of current densities.
  • Conventional bandgap reference circuits are explained in many texts, including P. Horowitz and W. Hill, The Art of Electronics , ⁇ Cambridge University Press, Cambridge, England, 1980, at 195-199, which is hereby incorporated by reference.
  • a basic two-transistor bandgap reference circuit is illustrated in Fig. 1.
  • a degree of compensation for the second order temperature-dependency of bandgap reference output voltage is obtained by incorporating into the reference circuit, in series with the usual emitter resistor, a second resistor (R b ) having a more positive temperature coefficient (TC) than the first resistor (R a , which has a nearly zero TC).
  • the current developed in the series combination of R a and R b is proportional to absolute temperature (PTAT).
  • PTAT absolute temperature
  • the circuit elements can be so arranged that the additional voltage component resulting from the parabolic term substantially counteracts the second order variation of the voltage produced by the basic bandgap circuit.
  • Resistor R b will generally be a diffused resistor, to attain a high, positive TC. The resistance of such a resistor is hard to control precisely and substantial variation in resistance value will occur in a manufacturing environment; moreover, such a resistance is not easily adjusted by laser trimming.
  • FIG. 4 A schematic circuit diagram of the Meijer et al. reference is shown in Fig. 4.
  • the four series-connected base-emitter junctions of transistors Q1-Q4 are biased at a PTAT current I PTAT, while the three series-connected base-emitter junctions of transistors Q12-Q14 are biased at a temperature-independent current, I REF .
  • I PTAT PTAT current
  • the thermal non-linearity in V BE about 25 percent less than that of a transistor biased at a constant current.
  • Subtracting the three base-emitter voltages with higher non-linearity from the four with the 25 percent lower non-linearity yields a voltage V′ BE which changes linearly with the temperature.
  • V′ BE The linear portion of the temperature dependence of V′ BE is conventionally cancelled by connecting a series resistor R1 in the path of the PTAT current.
  • the non-linearity of V BE (T) is somewhat dependent on the bias current, so that the compensation can be optimized by properly choosing that current.
  • B. S. Song and P. R. Gray have described yet another type of temperature-compensated bandgap reference which has been particularly adapted for use with CMOS technology. Their circuit employs a switched capacitor technique and does not provide continuous output, making it generally unsuitable for many cases where the present invention may be used (i.e., continuous analog environments).
  • B. S. Song, P. R. Gray "A Precision Curvature-Compensated CMOS Bandgap Reference," Proceedings of the 1983 IEEE International Solid-State Circuits Conference , February 25, 1983, at 240-241.
  • Another object of the invention is to improve the bandgap reference of U.S. Patent No. 4,250,445, to improve its performance under the conditions present in integrated circuit manufacturing processes.
  • the resistors 16 and 18 are thin-film resistors of low (i.e., near zero) TC, while resistor 22 (having resistance R b ) is a resistor having a substantial positive TC.
  • a test point 28 is added at the junction between resistors 18 and 22; the voltage at that test point is designated V comp .
  • the two thin-film resistors 16 and 18 are "trimmed" (i.e., adjusted) sequentially to minimize the first and second derivatives of the bandgap cell output as a function of temperature.
  • Laser trimming of thin-film resistors is commonly employed in today's integrated circuit manufacturing processes, so this approach is well-suited to mass production usage.
  • the technique is as follows: First, the approximate values for the three resistors 16, 18 and 22 are calculated from known formulae. Next, the voltage V comp is measured and resistance R2 is adjusted to cause V comp to have a defined voltage established by a relationship set forth below in the detailed description. Then the output voltage of the circuit, V BG , is measured and resistance R a is trimmed to adjust V BG to a value established by another relationship set forth below in the detailed description.
  • a bandgap voltage reference circuit, or cell, 10 embodying the present invention is shown.
  • This circuit is provided as a starting point, with resistors 16 and 18 to be trimmed to minimize thermal drift (Step 42 of the method of Fig. 6).
  • the reference circuit comprises first and second transistors 12 and 14, together with three resistors 16, 18 and 22.
  • the resistance values of the three resistors 16, 18 and 22 are, respectively, R2, R a and R b .
  • the areas of the emitters of transistors 12 and 14 are formed in a ratio A:1.
  • the bases of transistors 12 and 14 are connected together and to an output lead, or terminal, 24, at which the output voltage V BG , is provided.
  • the emitter of transistor 12 is connected to one end of resistor 16.
  • resistor 16 is connected to the emitter of transistor 14 and at node 26 to one end of a voltage divider formed by resistors 18 and 22.
  • the junction of resistors 18 and 22 provides a voltage divider tap which is supplied to a terminal or test point 28, at which the voltage v comp may be measured.
  • the base-emitter junction of transistor 14 is the junction whose temperature-dependent characteristics cause thermal drift and necessitate compensation.
  • Resistor 22 as taught in U.S. Patent No. 4,250,445, has a substantial positive temperature coefficient; a diffused resistor, for example, is well-suited to providing this characteristic.
  • the invention makes possible the use of a temperature coefficient for this resistor which is typically about 1500-2000 PPM, a value common to diffused resistors in standard silicon semiconductor processing.
  • R a R2[V go -V BEo +(M-1)V To ] 2V To ln(A) - R bo (1+2CT o )
  • M is the "curvature factor" of V BE for the semiconductor process used to make transistors 12 and 14
  • V go is the bandgap voltage using that semiconductor process
  • C is the first order temperature coefficient of the resistor material used for resistor 22
  • V BEo is the value of a single unit area V BE at temperature T o
  • V To kTo/q
  • the curvature factor M is obtained in a conventional fashion.
  • the trimming of resistor 18 essentially cancels out first order temperature dependencies (i.e., "slope" of V BG as a function of temperature) and the trimming of resistor 16 minimizes the second derivative of V BG as a function of temperature (i.e., "curvature").
  • the expression for resistance R bo is obtained by first solving for the first and second partial derivatives of the equation for V BG , as a function of temperature, and then setting those derivatives to zero. The latter step takes advantage of the fact that two trim points are available. The resulting equations can be solved for R bo and R a , to yield equations 32 and 34.
  • Resistors 16 and 18 may be (low TC) thin-film resistors which can easily be trimming using conventional laser trimming techniques, while resistor 22 generally will be a diffused resistor (to obtain the desired positive temperature coefficient), and such resistors are not subject to laser trimming. Further, the production variations in resistor 22 from the nominal, desired value, can be substantial. Thus, the technique of the present invention is particularly useful in the kind of manufacturing environment typically encountered in the production of IC bandgap references.
  • R bo R2 (M-1) 2(1+A)CT o ln(A)
  • R a R2[V go -V BEo +(M-1)V To ] (1+A)V To ln(A) - R bo (1+2CT o ) Similar equations can be derived to use when both the areas and the currents are different.
EP89903320A 1988-02-16 1989-01-26 Method for trimming a bandgap voltage reference circuit with curvature correction Expired - Lifetime EP0401280B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US156178 1988-02-16
US07/156,178 US4808908A (en) 1988-02-16 1988-02-16 Curvature correction of bipolar bandgap references
PCT/US1989/000330 WO1989007793A1 (en) 1988-02-16 1989-01-26 Curvature correction of bipolar bandgap references

Publications (2)

Publication Number Publication Date
EP0401280A1 EP0401280A1 (en) 1990-12-12
EP0401280B1 true EP0401280B1 (en) 1994-11-02

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Family Applications (1)

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EP89903320A Expired - Lifetime EP0401280B1 (en) 1988-02-16 1989-01-26 Method for trimming a bandgap voltage reference circuit with curvature correction

Country Status (5)

Country Link
US (1) US4808908A (ja)
EP (1) EP0401280B1 (ja)
JP (1) JPH03502843A (ja)
DE (1) DE68919215T2 (ja)
WO (1) WO1989007793A1 (ja)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7118273B1 (en) * 2003-04-10 2006-10-10 Transmeta Corporation System for on-chip temperature measurement in integrated circuits
US11675384B2 (en) 2021-10-05 2023-06-13 Macronix International Co., Ltd. Reference voltage generator with extended operating temperature range

Families Citing this family (56)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1227488B (it) * 1988-11-23 1991-04-12 Sgs Thomson Microelectronics Circuito di riferimento di tensione ad andamento in temperatura linearizzato.
US4954769A (en) * 1989-02-08 1990-09-04 Burr-Brown Corporation CMOS voltage reference and buffer circuit
US4939442A (en) * 1989-03-30 1990-07-03 Texas Instruments Incorporated Bandgap voltage reference and method with further temperature correction
DE4005756A1 (de) * 1989-04-01 1990-10-04 Bosch Gmbh Robert Praezisions-referenzspannungsquelle
US5013934A (en) * 1989-05-08 1991-05-07 National Semiconductor Corporation Bandgap threshold circuit with hysteresis
US5053640A (en) * 1989-10-25 1991-10-01 Silicon General, Inc. Bandgap voltage reference circuit
US5198747A (en) * 1990-05-02 1993-03-30 Texas Instruments Incorporated Liquid crystal display driver and driver method
US5015942A (en) * 1990-06-07 1991-05-14 Cherry Semiconductor Corporation Positive temperature coefficient current source with low power dissipation
US5029295A (en) * 1990-07-02 1991-07-02 Motorola, Inc. Bandgap voltage reference using a power supply independent current source
US5291122A (en) * 1992-06-11 1994-03-01 Analog Devices, Inc. Bandgap voltage reference circuit and method with low TCR resistor in parallel with high TCR and in series with low TCR portions of tail resistor
US5352973A (en) * 1993-01-13 1994-10-04 Analog Devices, Inc. Temperature compensation bandgap voltage reference and method
US5325045A (en) * 1993-02-17 1994-06-28 Exar Corporation Low voltage CMOS bandgap with new trimming and curvature correction methods
US5519308A (en) * 1993-05-03 1996-05-21 Analog Devices, Inc. Zero-curvature band gap reference cell
US5404096A (en) * 1993-06-17 1995-04-04 Texas Instruments Incorporated Switchable, uninterruptible reference generator with low bias current
BE1007853A3 (nl) * 1993-12-03 1995-11-07 Philips Electronics Nv Bandgapreferentiestroombron met compensatie voor spreiding in saturatiestroom van bipolaire transistors.
DE19528209C1 (de) * 1995-08-01 1996-08-29 Siemens Ag Schaltungsanordnung zur Basisvorspannungsversorgung von Stromquellentransistoren in Bipolar-IC-Schaltungen
US5767664A (en) * 1996-10-29 1998-06-16 Unitrode Corporation Bandgap voltage reference based temperature compensation circuit
US5933045A (en) * 1997-02-10 1999-08-03 Analog Devices, Inc. Ratio correction circuit and method for comparison of proportional to absolute temperature signals to bandgap-based signals
US5900772A (en) * 1997-03-18 1999-05-04 Motorola, Inc. Bandgap reference circuit and method
US6172555B1 (en) 1997-10-01 2001-01-09 Sipex Corporation Bandgap voltage reference circuit
US6157245A (en) * 1999-03-29 2000-12-05 Texas Instruments Incorporated Exact curvature-correcting method for bandgap circuits
IT1313386B1 (it) * 1999-06-09 2002-07-23 St Microelectronics Srl Metodo per ottenere un riferimento di tensione e di corrente costanteal variare della temperatura con un unico stadio band-gap.
US6232828B1 (en) * 1999-08-03 2001-05-15 National Semiconductor Corporation Bandgap-based reference voltage generator circuit with reduced temperature coefficient
US6201379B1 (en) 1999-10-13 2001-03-13 National Semiconductor Corporation CMOS voltage reference with a nulling amplifier
US6218822B1 (en) 1999-10-13 2001-04-17 National Semiconductor Corporation CMOS voltage reference with post-assembly curvature trim
US6198266B1 (en) 1999-10-13 2001-03-06 National Semiconductor Corporation Low dropout voltage reference
US6329804B1 (en) 1999-10-13 2001-12-11 National Semiconductor Corporation Slope and level trim DAC for voltage reference
IT1317567B1 (it) 2000-05-25 2003-07-09 St Microelectronics Srl Circuito di calibrazione di una tensione di riferimento a band-gap.
US6294902B1 (en) 2000-08-11 2001-09-25 Analog Devices, Inc. Bandgap reference having power supply ripple rejection
US6366071B1 (en) 2001-07-12 2002-04-02 Taiwan Semiconductor Manufacturing Company Low voltage supply bandgap reference circuit using PTAT and PTVBE current source
US6642699B1 (en) 2002-04-29 2003-11-04 Ami Semiconductor, Inc. Bandgap voltage reference using differential pairs to perform temperature curvature compensation
US6828847B1 (en) 2003-02-27 2004-12-07 Analog Devices, Inc. Bandgap voltage reference circuit and method for producing a temperature curvature corrected voltage reference
EP1501001A1 (en) * 2003-07-22 2005-01-26 STMicroelectronics Limited Bias Circuitry
US7543253B2 (en) * 2003-10-07 2009-06-02 Analog Devices, Inc. Method and apparatus for compensating for temperature drift in semiconductor processes and circuitry
US7012416B2 (en) * 2003-12-09 2006-03-14 Analog Devices, Inc. Bandgap voltage reference
US7211993B2 (en) * 2004-01-13 2007-05-01 Analog Devices, Inc. Low offset bandgap voltage reference
US7164259B1 (en) 2004-03-16 2007-01-16 National Semiconductor Corporation Apparatus and method for calibrating a bandgap reference voltage
US7193454B1 (en) 2004-07-08 2007-03-20 Analog Devices, Inc. Method and a circuit for producing a PTAT voltage, and a method and a circuit for producing a bandgap voltage reference
DE102004062357A1 (de) * 2004-12-14 2006-07-06 Atmel Germany Gmbh Versorgungsschaltung zur Erzeugung eines Referenzstroms mit vorgebbarer Temperaturabhängigkeit
US7411380B2 (en) * 2006-07-21 2008-08-12 Faraday Technology Corp. Non-linearity compensation circuit and bandgap reference circuit using the same
US8102201B2 (en) 2006-09-25 2012-01-24 Analog Devices, Inc. Reference circuit and method for providing a reference
US7576598B2 (en) * 2006-09-25 2009-08-18 Analog Devices, Inc. Bandgap voltage reference and method for providing same
US7714563B2 (en) * 2007-03-13 2010-05-11 Analog Devices, Inc. Low noise voltage reference circuit
US20080265860A1 (en) * 2007-04-30 2008-10-30 Analog Devices, Inc. Low voltage bandgap reference source
US7605578B2 (en) 2007-07-23 2009-10-20 Analog Devices, Inc. Low noise bandgap voltage reference
US7598799B2 (en) * 2007-12-21 2009-10-06 Analog Devices, Inc. Bandgap voltage reference circuit
US7612606B2 (en) * 2007-12-21 2009-11-03 Analog Devices, Inc. Low voltage current and voltage generator
US7902912B2 (en) * 2008-03-25 2011-03-08 Analog Devices, Inc. Bias current generator
US7750728B2 (en) * 2008-03-25 2010-07-06 Analog Devices, Inc. Reference voltage circuit
US7880533B2 (en) * 2008-03-25 2011-02-01 Analog Devices, Inc. Bandgap voltage reference circuit
EP2648061B1 (en) * 2012-04-06 2018-01-10 Dialog Semiconductor GmbH Output transistor leakage compensation for ultra low-power LDO regulator
US20130300395A1 (en) * 2012-05-11 2013-11-14 Gregory A. Maher Accessory detection over temperature
US9740229B2 (en) * 2012-11-01 2017-08-22 Invensense, Inc. Curvature-corrected bandgap reference
US10156862B2 (en) * 2015-12-08 2018-12-18 Dialog Semiconductor (Uk) Limited Output transistor temperature dependency matched leakage current compensation for LDO regulators
TWI792977B (zh) 2022-04-11 2023-02-11 立錡科技股份有限公司 具有高次溫度補償功能的參考訊號產生電路
CN117270620B (zh) * 2023-11-21 2024-03-08 西安航天民芯科技有限公司 一种二阶曲率补偿齐纳基准供压电路

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3648153A (en) * 1970-11-04 1972-03-07 Rca Corp Reference voltage source
US4433283A (en) * 1981-11-30 1984-02-21 International Business Machines Corporation Band gap regulator circuit
US4472675A (en) * 1981-11-06 1984-09-18 Mitsubishi Denki Kabushiki Kaisha Reference voltage generating circuit
US4590418A (en) * 1984-11-05 1986-05-20 General Motors Corporation Circuit for generating a temperature stabilized reference voltage
US4622512A (en) * 1985-02-11 1986-11-11 Analog Devices, Inc. Band-gap reference circuit for use with CMOS IC chips
US4634959A (en) * 1985-12-16 1987-01-06 Gte Communication Systems Corp. Temperature compensated reference circuit
US4714872A (en) * 1986-07-10 1987-12-22 Tektronix, Inc. Voltage reference for transistor constant-current source

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5913052B2 (ja) * 1975-07-25 1984-03-27 日本電気株式会社 基準電圧源回路
US4250445A (en) * 1979-01-17 1981-02-10 Analog Devices, Incorporated Band-gap voltage reference with curvature correction
US4362984A (en) * 1981-03-16 1982-12-07 Texas Instruments Incorporated Circuit to correct non-linear terms in bandgap voltage references

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3648153A (en) * 1970-11-04 1972-03-07 Rca Corp Reference voltage source
US4472675A (en) * 1981-11-06 1984-09-18 Mitsubishi Denki Kabushiki Kaisha Reference voltage generating circuit
US4433283A (en) * 1981-11-30 1984-02-21 International Business Machines Corporation Band gap regulator circuit
US4590418A (en) * 1984-11-05 1986-05-20 General Motors Corporation Circuit for generating a temperature stabilized reference voltage
US4622512A (en) * 1985-02-11 1986-11-11 Analog Devices, Inc. Band-gap reference circuit for use with CMOS IC chips
US4634959A (en) * 1985-12-16 1987-01-06 Gte Communication Systems Corp. Temperature compensated reference circuit
US4714872A (en) * 1986-07-10 1987-12-22 Tektronix, Inc. Voltage reference for transistor constant-current source

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7118273B1 (en) * 2003-04-10 2006-10-10 Transmeta Corporation System for on-chip temperature measurement in integrated circuits
US11675384B2 (en) 2021-10-05 2023-06-13 Macronix International Co., Ltd. Reference voltage generator with extended operating temperature range

Also Published As

Publication number Publication date
DE68919215D1 (de) 1994-12-08
JPH03502843A (ja) 1991-06-27
US4808908A (en) 1989-02-28
EP0401280A1 (en) 1990-12-12
DE68919215T2 (de) 1995-05-18
WO1989007793A1 (en) 1989-08-24

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